Adaptive flow control via Interest aggregation in CCN

Abstract

In CCN (Content-Centric Networking), one request retrieves at most one data packet. Although the design intent of such rule is to maintain flow balance across the network, it may cause significant underutilization of Data downlink, especially in networks with asymmetric up/down link speed such as cellular networks. This paper describes an adaptive flow control mechanism where multiple Data messages per Interest are allowed in an adaptive manner without violating the operational principle of original CCN protocol. The performance of proposed scheme is demonstrated in an experimental testbed implementation built with CCNx open source code and its extension.

Adaptive interest adjustment in CCN flow control

“…The maximum number of Interests sent simultaneously determines the expected link utilization as with the maximum receive window size defined in TCP [8]. As identified in [11], however, the problem with the pipeline-based flow control is that there can be too many back-to-back Interest messages. Window-based flow control in [11] solves such problem of having too many Interest messages by allowing one-to-many message exchange.…”

“…Even with the symmetric links, occupying network resources with compressible data, e.g., transmitting multiple Interest messages requesting a range of Data segments may be undesirable. A flow control mechanism for CCN has been proposed in [11], which mitigates the underutilization problem of the existing one-to-one message exchange operation of the CCN protocol by allowing a single Interest to request multiple data segment. However, adaptively finding an optimal value for the next Interest message transmission time has been left for further study [11].…”

“…A flow control mechanism for CCN has been proposed in [11], which mitigates the underutilization problem of the existing one-to-one message exchange operation of the CCN protocol by allowing a single Interest to request multiple data segment. However, adaptively finding an optimal value for the next Interest message transmission time has been left for further study [11]. In this paper, we propose an adaptive scheme which enables uplink transmission of just enough number of Interest messages while fully utilizing the downlink capacity.…”

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We propose an adaptive Interest (or content request message) adjustment scheme as an additional enhancement to the CCN (Content-Centric Networking) flow control algorithm described in [11], where the one-to-one message exchange nature of CCN was re-architected to enable more effective one-to-many message exchange. The proposed scheme adaptively determines the optimal transmission time of successive Interest messages, thus effectively adjusts the transmission window size to further enhance link utilization while preserving the benefit of reducing the total number of Interest messages.

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Are Information-Centric Networks Video-Ready?

“…ADSL or satellite networks. These issues can be dealt by relaxing the strict one-to-one mapping between Interests and Data, for example introducing Interest Aggregation [21] or Persistent Interests [18]. With Interest Aggregation, a single Interest requests multiple Data packets at once whereas Persistent Interests mimic IP's channel mode and request all packets belonging to a stream.…”